The present invention relates to a cutting apparatus for cigarette making machines for vertically cutting a horizontally travelling cigarette rod into cigarettes.
Simple cutting apparatuses of this type are conventionally used, in which a cutting edge is rotated and moved in the same direction as a cigarette rod by means of a universal joint to cut the cigarette rod which is guided in a ledger. These apparatuses are disclosed in, for example, U.S. Pat. No. 3,176,560 and Japanese Patent Publication No. 9840/76. In these apparatuses, however, if the universal joint is driven at high speed, its vibration and hence the vibration of the cutting edge are augmented resulting in the cut faces of the cigarettes being jagged, which leads to the lowering of the commercial value of the cigarettes.
In order to eliminate the above drawback, apparatuses have been developed in which a rotating member with a tilted rotating shaft is used in place of the universal joint so that the cutting edge is mounted on the rotating member and moved at a uniform speed, as disclosed in U.S. Pat. Nos. 3,604,162 and 3,753,379. In these apparatuses, the ledger is moved for acceleration and deceleration as the cutting edge moves. These apparatuses are not, however, provided with fully effective means for movably supporting the ledger for acceleration and deceleration. Moreover, such a manner of moving the ledger is not satisfactory because it will place restrictions on high-speed operation.
Apparatuses of another type, as are disclosed in U.S. Pat. Nos. 3,479,913, 3,728,923, 3,772,952, 3,863,536 and 3,956,955, are conventionally known in which the ledger is rotatable. However, the apparatuses of this type cannot easily synchronize the movements of the ledger and the cutting edge at high speed, and are unfit for high-speed operation. In this arrangement, moreover, the ledger cannot cover the whole circumference of the cigarettes, and the cut faces of the cigarettes are not as smooth as they should be.